A chainsaw used to cut an object to be worked such as wood has a loop-like saw chain provided with a blade portion projecting outward, namely, a chainsaw. The saw chain is movably wound around a guide bar having a base end portion fixed to a housing, and it is rotationally driven by a driving source provided within the housing. As the driving source, an engine or an electric motor is used. As the chainsaw using the electric motor as the driving source, there is one described in Japanese Patent Application Laid-Open Publication No. 2011-136384 (PTL 1).